Stroke and TIA Flashcards
What is the second leading cause of death worldwide?
Stroke
What is dysphasia?
Language disorder
Deficiency in generation of speech
Sometimes also comprehension
Due to brain disease/damage
What is expressive dysphasia?
Difficulty in putting words together to make meaning
What is receptive dysphasia?
Difficulty in comprehension
What is dysarthria?
Speech disorder caused by disturbance of muscular control
What is dysphonia?
Difficulty speaking due to physical disorder of
- Mouth/
- Tongue/
- Throat/
- Vocal cords
What does the acronym FAST stand for?
F - facial weakness - Can person smile - Has mouth/eye drooped A - arm weakness - Can person raise both arms? S - speech difficulty - Can person speak clearly and understand what you say? T - time to act fast
Why is it important to know the exact time of onset of symptoms in stroke?
Because treatment available very time critical
How can you assess facial droop?
Asymmetry in nasolabial folds
If subtle, get patient to smile
What type of lesion is indicated if the upper half of the face is spared?
Upper motor neuron lesion on contralateral side
What type of lesion is indicated if the whole half of the face is affected?
Lower motor neuron lesion on ipsilateral side
How can arm drift be used to assess weakness in an arm in the assessment of a possible stroke?
Ask patient to close eyes and hold out both arms, palms facing up
Arm on weaker side pronates and drifts downwards
What type of dysphasia Broca’s dysphasia?
Expressive
What type of dysphasia is Wernicke’s dysphasia?
Receptive
What is a silent stroke?
May not have much of deficit
May be difficult to elicit deficit if present even 1 hour later
Still have tissue infarction on imaging
Define stroke
Brief episodes <24 hours with brain injury
Define transient ischaemic attack (TIA)
Brief neurological episodes, usually <24 hours, without damage on imaging
What does a code stroke in the emergency department mean?
Urgent triage and high priority Mobilise stroke team IV - Glucose - Routine biochemistry - Full blood exam (FBE) ECG Accurate clinical diagnosis - Exclude mimics Urgent CT
Why is blood glucose measured in a possible stroke patient?
Hypoglycaemia = great mimic, especially of stroke
Why is an FBE performed in a stroke patient?
Platelet levels - If known coagulopathy - On anticoagulant Include INR Both assess risk of bleeding because of thrombolysis
Why is a CT scan performed?
To exclude haemorrhage
Doesn’t matter if you accidentally thrombolyse a TIA/stroke mimic
- But important not to thrombolyse haemorrhage
When does thrombolysis lose its benefit-to-risk ratio?
After 4.5 hours
How do you predict a stroke has occurred, and not a mimic?
Exact time of onset Patient could recall exactly what they were doing when symptoms started Well in last week Definite focal symptoms/signs Worse NIH stroke score (NIHSS)
How do you predict a mimic has occurred, and not a stroke?
Known cognitive impairment Lost consciousness/seizure at onset Patient could still walk No lateralising symptoms Confusion Non-vascular, or no neurological signs
Does a CT scan help in the diagnosis of a stroke?
No, remains clinical diagnosis
Scan done only to exclude haemorrhage
Signs of infarct can take up to 72 hours to develop
What are the three major stroke types?
Ischaemic stroke = cerebral infarction
Intracerebral haemorrhage
Subarachnoid haemorrhage
What are the common types of ischaemic stroke?
Large artery thromboembolism Cardiogenic embolism Small vessel (lacunar) infarction Rarer causes Unclassified/cryptogenic
What are the common types of intracerebral haemorrhage?
Deep hypertensive location
Lobar
What are the common types of subarachnoid haemorrhage?
Aneurysm
Arteriovenous malformation
Other
What is a larger artery thromboembolism?
Cortical infarction
More than 50% relevant large artery stenosis
Absence of cardiac source
What is a cardiogenic embolism?
Cortical infarction
Cardiac source
Absence of large artery disease
What is the most common cardiac source of a cerebral infarction?
Atrial fibrillation
What is a lacunar infarction?
Subcortical infarction
Absence of large artery/cardiac source
Clinical syndromes
What are some rare causes of ischaemic stroke?
Arterial dissection
Drugs
Vasculitis
Rarer arteriopathies; eg: Moyamoya disease
What is the most lethal stroke subtype?
Haemorrhage
What is a deep intracerebral haemorrhage?
Putamen Thalamus Brainstem Cerebellum Usually due to hypertension and rupture of deep penetrating arteries
What is a lobar intracerebral haemorrhage?
Superficial Often secondary to - Amyloid angiopathy - Tumour - Arteriovenous malformation - Aneurysm
What does stroke evolution result in?
Increased lesion volume > worse outcome
What is the aim of therapies for ischaemic stroke and intracerebral haemorrhage?
Limiting stroke growth
What is IV tPA?
Thrombolytic
What is hemicraniectomy?
Skull flap removed for some days, allowing swelling to subside
What are the non-modifiable risk factors for ischaemic stroke?
Age Gender Family history Ethnicity Contraceptive use
What are the established modifiable risk factors for inschaemic stroke?
Hypertension Diabetes Smoking Atrial fibrillation/heart disease Hypercholesterolaemia Alcohol consumption Prothrombotic factors Prior TIA Prior stroke
What are the possible modifiable risk factors for ischaemic stroke?
Physical inactivity Obesity Dietary factors Infection Stress Sleep apnoea Socioeconomic status
What are the main modifiable risk factors for ischaemic stroke?
Smoking
Hypertension
Diabetes
Obesity
Do antihypertensive drugs reduce the risk of primary stroke?
Yes, by 40%
Is there an indication for antiplatelet treatment in ischaemic stroke?
No clear indication in low-intermediate risk
In high risk, consider aspirin
Does warfarin decrease the risk of stroke?
Yes
What are the classes of the new oral anticoagulants?
Direct thrombin inhibitor
Factor Xa inhibitors
What is the drug class of dabigatran?
Direct thrombin inhibitor
What is the drug class of rivaroxaban?
Factor Xa inhibitor
What is the drug class of apixaban?
Factor Xa inhibitor
What is the advantage of the new oral anticoagulants over warfarin?
Less likely to cause intracerebral haemorrhages
What is the CHADS2 scoring system?
Measure for calculating risk of haemorrhage
How is secondary prevention carried out in stroke?
Tailored to stroke pathogenesis in individual
When should secondary prevention for stroke start?
In hospital
Describe in general terms the secondary prevention of stroke
Lower blood pressure Control cholesterol with statins Antiplatelet therapy Control atrial fibrillation with anticoagulation Carotid revascularisation - Endarterectomy - Stenting
